Cladding sheets

ABSTRACT

A method of bending a corrugated sheet about an axis extending at right angles to the corrugations is disclosed wherein a plurality of rib formations are pressed in those corrugations having their apices nearest the axis, the rib formations all projecting from the same surface of the sheet relative to the axis and extending at an angle to the corrugations over at least part of the side portions and at least part of the intermediate portions of the corrugations. In one form of the invention the corrugated sheet comprises a metal cladding sheet. Also disclosed is a corrugated sheet bent about an axis extending at right angles to the corrugations including a plurality of rib formations projecting from the same surface of the sheet when viewed from the axis, the rib formations being at an angle to the corrugations and extending over at least part of the side portions and at least part of the intermediate portions of the corrugations.

United States Patent n91 Seeff [451 July 23, 1974 CLADDING SHEETS [76] Inventor: Morris Seeff, 11 First Ave.,

Houghton, Johannesburg, Transvaal, South Africa 22 Filed: Dec.11,l973

21 App]. No.: 423,764

Related US. Application Data [63] Continuation of Ser. No. 239,166, March 29, 1972,

abandoned.

[52] US. Cl. 29/180 SS, 52/630, 72/177, 72/379 [51] Int. Cl B21d 13/10 [58] Field of Search 29/155, 183, 180 SS; 52/630; 72/177, 196, 379, 385

[56] References Cited UNITED STATES PATENTS 2,370,702 3/1945 Yoder 72/177 2,775,284 12/1956 Hermann 72/196 3,059,733 10/1962 Hermann 52/630 3,111,788 11/1963 Ouellet 52/630 3,395,438 8/1968 Seeff..- 52/630 3,664,170 5/1972 Davis 72/379 Primary Examiner-Lowell A. Larson Attorney, Agent, or Firm-Merchant, Gould, Smith & Edel [5 7 ABSTRACT A method of bending a corrugated sheet about an axis extending at right angles to the corrugations is disclosed wherein a plurality of rib formations are pressed in those corrugations having their apices nearest the axis, the rib formations allprojecting from the same surface of the sheet relative to the axis and extending at an angle to the corrugations over at least part of the side portions and at least part of the intermediate portions of the corrugations.

In one form of the invention the corrugated sheet comprises a metal cladding sheet.

Also disclosed is a corrugated sheet bent about an axis extending at right angles to the corrugations including a plurality of rib formations projecting from the same surface of the sheet when viewed from the axis, the rib formations being at an angle to the corrugations and extending over at least part of the side portions and at least part of the intermediate portions of the corrugations.

16 Claims, 6 Drawing Figures CLADDING SHEETS This is a continuation of application Ser. No. 239,166, filed Mar. .29, 1972 now abandoned.

BACKGROUND OF THE INVENTION This invention relates to metal cladding sheets and particularly to the bending of corrugated metal cladding sheets.

For purposes of this specification, the term corrugated sheet includes a'sheet of sinusoidal, rectangular, trapezoidal or ribbed corrugated cross-sectional configuration and a corrugation is considered to comprise a pair of spaced side portions and an intermediate portion extending between the side portions. The same corrugation hence defines a valley when viewed from one side of the sheet and a peak or raised formation when viewed from the opposite side of the sheet. Adjacent corrugations hence have a side portion in common.

With sinusoidal corrugations the intermediate portion is considered to be located in the zone of the apex of the valley or peak. In this specification the term apex" is meant to refer to the uppermost or lowermost part of the peak or valley respectively.

Corrugated metal cladding sheets are normally provided in planar lengths but it is frequently desirable to bend such sheets into curved forms of predetermined radii of curvature to meet particular requirements.

It is known to bend sheets of the aforesaid kind about an axix extending at right angles to the corrugations by pressing transversely extending rib formations in the intermediate portions of the corrugations together with transversely extending indentations in the side portions.

It has, however, been found with this known arrangement that a line of weakness tends to develop where the rib formations on the intermediate portion meet the indentations on the side portions. I

It is accordingly an object of this invention to provide a method of bending corrugated sheets as herein defined with which the aforesaid problem will be overcome or at least minimized.

SUMMARY OF THE INVENTION According to the invention a method of bending a corrugated sheet as herein defined about an axis extending at right angles to the corrugations, includes the step of pressing in those corrugations having their apices nearest the axis a plurality of rib formations projecting from the same surface of the sheet relative to the axis, the rib formations being at an angle to the corrugations and extending over at least part of the side portions at at least part of the intermediate portions of the corrugations.

Because the rib formations project from the same surface of the sheet the possibility of a line of weakness forming where the formation on the side portion meets the formation on the intermediate portion is minimized.

Further the presence of a rib extending continuously over at least the zone where a side portion meets an intermediate portion gives additional strength in this zone.

Further according to the invention the rib formations are in rows, each row being formed in one operation which is repeated at spaced intervals along the .sheet in a direction parallel to the corrugations to give the desired degree of bending.

Alternatively the rib formations may be in rows with a plurality of rows being formed in one operation which is repeated at spaced intervals along the sheet in a direction parallel to the corrugations to give the desired degree of bending.

Preferably the rib formations on the side portions in the direction away from the intermediate portions decrease in width and in height relative to the surface from which they project.

Preferably also, the rib formations are pressed to project from the surface on the other side of the sheet when viewed from the axis.

The rib formations are preferably discontinued over at least part of the intermediate portions to define a drainage channel.

Preferably, also, the rib formations extend at right angles to the corrugations.

Further according to the invention the method includes the step of feeding the sheet in a direction parallel to its corrugations between a pair of mating die members adapted to press the rib formations in the corrugations.

It will be appreciated that the method may also be employed to bend an uncorrugated metal cladding sheet about an axis by, providing the sheet with a plurality of corrugations as herein defined extending at right angles to the axis and pressing in those corrugations having their apices nearest the axis, a'plurality of rib formations projecting from the same surface of the sheet when viewed from the axis, the rib formations being at an angle to the corrugations and extending over at least part of theside portions and at least part of the intermediate portions of the corrugations.

The invention includes within its scope a bent corrugated sheet made in accordance with the aforesaid method.

BRIEF DESCRIPTION OF THE DRAWINGS The'invention will now be further described by way of example with reference to the accompanying drawings in which:

FIG. 1 shows in cross-section part of a corrugated sheet of metal cladding material to be bent;

FIG. 2 is a similar view as that of FIG. 1 showing the sheet after bending;

FIG. 3 is a perspective view showing part of the sheet of FIG. 1 in more detail;

F IG. 4 shows in cross-section a pair of mating die formations suitable for bending a sheet such as that of FIG. 1;

FIG. 5 shows in cross-section part of a corrugated sheet of metal cladding material of different configuration to that of the sheet of FIG. 1 after bending; and

FIG. 6 is a perspective view showing part of the sheet of FIG. 5 in more detail.

DESCRIPTION OF THE PREFERRED EMBODIMENT the intermediate portions and side portions 4 of each raised formation 3.

As canbe seen from FIGS. 2 and 3 rib formations 8, which are of substantially triangular configuration in cross-section, project from the same surface of sheet 1 relative to the axis of curvature. Furthermore that portion of formation 8 which extends along side portions 4 decreases in a direction away from intermediate portion 5 in width andin height relative to thesur'face from which they are pressed.

Because of the provision of formations 8 in the material of sheet 1 in this manner sheet 1 is curved according to known principles in the longitudinal direction about an axis extending at right angles to corrugations 2 as shown in FIG. 3.

Furthermore because'each formation 8 is continuous in the zone 13 where side portions 4 and intermediate portions 5 meet the formation of the aforesaid line of weakness found with the conventional arrangements is avoided or at least minimized.

The operative face of die member 7 which includes a plurality of spaced raised formations 9 each adapted to engage adjacent corrugations 2 of a sheet 1 located above it, is provided with upstanding formations 10 extending between adjacent raised formations 9. Formations 10 are of complementary configuration to the formations 8 to be pressed on sheet 1.

Each formation 10 is discontinued along its central portion to define an indentation 11 allowing for a centrally located longitudinally extending groove 12 to be pressed in intermediate portion 5 of sheet 1. Groove 12 serves the purpose of a drainage channel in sheet 1. The operative face of die member 6 is of complementary configuration to that of member 7.

Members 6 and 7 are adapted to be mounted on a press in a conventional manner to define a nipping zone between them in which a sheet such as sheet 1 may pass to be formed between the co-acting members 6 and 7 as they close on each other.

It will be appreciated that members 6 and 7 may be provided with a single row of formations 10 to be able to press a single row of formations 8 at a time on sheet 1 or it may be provided with a plurality of parallel spaced formations 10 to be able to press a plurality of rows of formations 8 at a time on sheet 1.

The radius of curvature for bending sheet 1 may be varied by varying the distance separating adjacent formations 8 thereon.

The sheet 1 shown in FIGS. 5 and 6, which is of different cross-sectional configuration to that of the previous figures, may be similarly bent by forming a plurality of rib formations 8 thereon in a similar manner. It will beappreciated that the mating die membersemployed for bending this sheet will have operative faces complementary in configuration to that of the sheet to be bent.

The invention also includes within its scope apparatus for bending a sheet substantially as herein described.

Furthermore, the invention also includes within its scope sheets when bent according to any of the aforesaid methods.

Curved sheets substantially as herein described are also intended to be included in the scope of this invention.

It will be appreciated that while the term cladding material has been used in this specification to include roofing sheets and the like it is to be understood that the use of the product for reservoirs, storage drums, sheds, vehicle canopies or other structures of a similar nature are to be included in the scope of this invention and the term cladding material.

What is claimed is:

1. A method of bending a sheet having a plurality of corrugations longitudinally extending at least over that area of the sheet to be bent, each corrugation having a pair of side portions joining at an apex and said sheet having intermediate portions continuously connecting adjacent side portions of different ones of said corrugations, said method being operable'to bend .the corrugated sheet about an axis extending at right angles to the corrugations and comprising: pressing, by means of a tool operating within the cavities defined by those corrugations having their apices furthest away from the axis a plurality of rib formations into those corrugations having their apices nearest the axis so as to project the rib formations from the same surface of the sheet relative to the axis, and at an angle to the corrugations and continuously extending over at least part of each side portion and at least part of each intermediate portion.

2. A method of bending a corrugated sheet according to claim 1, wherein the pressing of rib formations into the sheet comprises the steps of:

a. providing a first die member having a generally planar base, raised formations projecting from said base and spaced and contoured for general mating engagement with the wall surfaces within said cavities, and upstanding formations projecting from saidbase and extending between adjacent ones of said raised formations;

b. causing said first die member to operatively engage said corrugated sheet on one side thereof such that spaced raised formations are inserted within said plurality of cavities and engage the inside walls thereof and such that said upstanding formations are in engagement with those corrugations having their apices nearest said axis;

c. causing a second die member of geometric configuration complimentary to said first die member to operatively engage said corrugated sheet inexact opposing relationship to said first die member such that said sheet is sandwiched therebetween; and

d. forcing said first and second die members toward mating engagement with one another with said corrugated sheet sandwiched therebetween such that said raised spaced formations and said upstanding formations impress said plurality of rib formation into said sheet.

3. A method of bending a corrugated sheet according to claim 1, comprising forming the rib formations in rows, each row being formed in one operation and extending across the entire sheet, and repeatedly forming said rows at spaced intervals along the sheet in a direction parallel to the corrugations to give the desired degree of bending.

height relative to the surface from which they project and in the direction away from the intermediate portions.

6. A method of bending a corrugated sheet according to claim 1, comprising pressing the rib formations so as to project from the sheet surfaceon that side of the sheet opposite the axis.

7. A method of bendinga corrugated sheet according to claim 1, comprising discontinuing formation of the rib formations over at least part of the intermediate portions of the sheet, to define a drainage channel.

8. A method of bending a corrugated sheet according to claim 1, comprising forming the rib formations so as to extend at right angles to the corrugations. I

9. A method of bending a corrugated sheet according to claim 1, including the step of feeding the sheet in a direction parallel to its corrugations between a pair of mating die members adapted to press the rib formations in the corrugations.

10. A method of bending a corrugated sheet according to claim 1, comprising forming the rib'formation in the side portion of each corrugation and in each intermediate portion, so as to be continuous at least over that area where two adjacent side and intermediate portions meet.

11. A method of bending a narrow ribbed sheet having a plurality of narrow rib corrugations longitudinally extending at least over that area of the sheet to be bent, each narrow rib corrugation having a pair of side portions joining at an apex and said sheet having intermediate portions continuously connecting adjacent side portions of different ones of said corrugations, said method being operable to bend the corrugated narrow ribbed sheet about an axis extending at right angles to the corrugations and positioned opposite that side of said sheet from which said narrow rib corrugation apices project, comprising: pressing, by means of a tool operating within the cavities defined by said joined side portions of those narrow ribbed corrugations having their apices furthest away from the axis, a plurality of rib formations into said side portions of the narrow rib corrugations and into said intermediate portions of the narrow rib corrugations so as to project the pressed rib formations from the same surface of the sheet relative to the axis, and at an angle to the corrugations and continuously extending over at least part of each side portion and over at least part of each intermediate portion.

12. A continuous corrugated sheet having a plurality of corrugations each having a pair of side portions joining at an apex running longitudinally with the corrugation and having intermediate portions connecting the side portions of adjacent corrugations, said sheet being curved about an axis extending at right angles to the corrugations, and including a plurality of rib formations formed therein and projecting from the same surface of the sheet when viewed from the axis, each rib formation being at an angle to the corrugations and continuously extending over at least part of each side portion and at least part of each intermediate portion.

13. A continuous corrugated sheet according to claim 9, wherein the rib formations in the side portions of the corrugations, and in the direction away from the intermediate portions of the sheet, decrease in width and in height relative to the surfaces from which they project.

14. A continuous corrugated sheet according to claim 9, wherein the rib formations are discontinuous over at least part of the intermediate portions to define a drainage channel.

15. A continuous corrugated sheet according to claim 9, wherein the rib formations extend at right angles to the corrugations.

16. A method of bending a metal cladding sheet about an axis comprising:

a. providing the sheet with a plurality of corrugations longitudinally extending at right angles to a bending axis, each corrugation having a pair of side portions joining at an apex, with intermediate portions of the sheet connecting adjacent side portions of different ones of said corrugations; and

b. pressing into those corrugations having their apices nearest the axis, a plurality of rib formations so as to project the rib formations from the same surface of the sheet relative to the axis, and at an angle to the. corrugations and continuously extending over at least part of each side portion and at least part of each intermediate portion. 

2. A method of bending a corrugated sheet according to claim 1, wherein the pressing of rib formations into the sheet comprises the steps of: a. providing a first die member having a generally planar base, raised formations projecting from said base and spaced and contoured for general mating engagement with the wall surfaces within said cavities, and upstanding formations projecting from said base and extending between adjacent ones of said raised formations; b. causing said first die member to operatively engage said corrugated sheet on one side thereof such that spaced raised formations are inserted within said plurality of cavities and engage the inside walls thereof and such that said upstanding formations are in engagement with those corrugations having their apices nearest said axis; c. causing a second die member of geometric configuration complimentary to said first die member to operatively engage said corrugated sheet in exact opposing relationship to said first die member such that said sheet is sandwiched therebetween; and d. forcing said first and second die members toward mating engagement with one another with said corrugated sheet sandwiched therebetween such that said raised spaced formations and said upstanding formations impress said plurality of rib formation into said sheet.
 3. A method of bending a corrugated sheet according to claim 1, comprising forming the rib formations in rows, each row being formed in one operation and extending across the entire sheet, and repeatedly forming said rows at spaced intervals along the sheet in a direction parallel to the corrugations to give the desired degree of bending.
 4. A method of bending a corrugated sheet according to claim 1, comprising forming the rib formations in rows extending across the entire sheet, with a plurality of said rows being formed in one operation, and repeatedly forming said plurality of rows at spaced intervals along the sheet in a direction parallel to the corrugations to give the desired degree of bending.
 5. A method of bending a corrugated sheet according to claim 1, comprising pressing into the side portions said rib formations which decrease in width and in height relative to the surface from which they project and in the direction away from the intermediate portions.
 6. A method of bending a corrugated sheet according to claim 1, comprising pressing the rib formations so as to project from the sheet surface on that side of the sheet opposite the axis.
 7. A method of bending a corrugated sheet according to claim 1, comprising discontinuing formation of the rib formations over at least part of the intermediate portions of the sheet, to define a drainage channel.
 8. A method of bending a corrugated sheet according to claim 1, comprising forming the rib formations so as to extend at right angles to the corrugations.
 9. A method of bending a corrugated sheet according to claim 1, including the step of feeding the sheet in a direction parallel to its corrugations between a pair of mating die members adapted to press the rib formations in the corrugations.
 10. A method of bending a corrugated sheet according to claim 1, comprising forming the rib formation in the side portion of each corrugation and in each intermediate portion, so as to be continuous at least over that area where two adjacent side and intermediate portions meet.
 11. A method of bending a narrOw ribbed sheet having a plurality of narrow rib corrugations longitudinally extending at least over that area of the sheet to be bent, each narrow rib corrugation having a pair of side portions joining at an apex and said sheet having intermediate portions continuously connecting adjacent side portions of different ones of said corrugations, said method being operable to bend the corrugated narrow ribbed sheet about an axis extending at right angles to the corrugations and positioned opposite that side of said sheet from which said narrow rib corrugation apices project, comprising: pressing, by means of a tool operating within the cavities defined by said joined side portions of those narrow ribbed corrugations having their apices furthest away from the axis, a plurality of rib formations into said side portions of the narrow rib corrugations and into said intermediate portions of the narrow rib corrugations so as to project the pressed rib formations from the same surface of the sheet relative to the axis, and at an angle to the corrugations and continuously extending over at least part of each side portion and over at least part of each intermediate portion.
 12. A continuous corrugated sheet having a plurality of corrugations each having a pair of side portions joining at an apex running longitudinally with the corrugation and having intermediate portions connecting the side portions of adjacent corrugations, said sheet being curved about an axis extending at right angles to the corrugations, and including a plurality of rib formations formed therein and projecting from the same surface of the sheet when viewed from the axis, each rib formation being at an angle to the corrugations and continuously extending over at least part of each side portion and at least part of each intermediate portion.
 13. A continuous corrugated sheet according to claim 9, wherein the rib formations in the side portions of the corrugations, and in the direction away from the intermediate portions of the sheet, decrease in width and in height relative to the surfaces from which they project.
 14. A continuous corrugated sheet according to claim 9, wherein the rib formations are discontinuous over at least part of the intermediate portions to define a drainage channel.
 15. A continuous corrugated sheet according to claim 9, wherein the rib formations extend at right angles to the corrugations.
 16. A method of bending a metal cladding sheet about an axis comprising: a. providing the sheet with a plurality of corrugations longitudinally extending at right angles to a bending axis, each corrugation having a pair of side portions joining at an apex, with intermediate portions of the sheet connecting adjacent side portions of different ones of said corrugations; and b. pressing into those corrugations having their apices nearest the axis, a plurality of rib formations so as to project the rib formations from the same surface of the sheet relative to the axis, and at an angle to the corrugations and continuously extending over at least part of each side portion and at least part of each intermediate portion. 